1. Field of the Invention
The present invention is generally related to a surge suppressor circuit and, more particularly, to a semiconductor device which provides a dual Zener diode arrangement constructed in a manner to minimize current leakage, reduce edge cracking, efficiently dissipate heat, provide stable and reliable operation in a hostile environment and maintain a uniform and consistent breakdown voltage. It should be understood that although diodes that ar designed and specified to operate continuously in a voltage breakdown mode are typically referred to as Zener diodes that terminology is not always correct. The mechanisms responsible for electrical breakdown in silicon include both avalanche and Zener types of breakdowns. These breakdowns occur at different value of electric field strength. Zener breakdown usually occur below 5 or 6 volts while avalanche breakdown occurs above 5 or 6 volts. According to this definition, the junction diodes of the present invention would more properly be described as operating under an avalanche mechanism. However, throughout the following description of the present invention, these diodes will be referred to as Zener diodes, following common terminology.
2. Description of the Prior Art
It is well known in the prior art to utilize two Zener diodes in an opposing polarity association for the purpose of providing surge suppression in an integrated circuit. It is also well known to those skilled in the art to provide this type of dual Zener arrangement in a solid state device. However, known constructions of dual Zener packages exhibit disadvantages during operation. These disadvantages will be described in greater detail below in conjunction with FIGS. 4, 5 and 6.